Under normal circumstances, the molybdenum target is generally not too harmful, but has a certain degree of radiation, it is not recommended to do frequently. Mammogram belongs to the more common means of physical examination of the breast, the current diagnosis of breast disease of choice is also internationally recognized as the most effective means of breast screening, non-invasive means of detection, relatively small pain, and high resolution, repeatability. Mammography belongs to a kind of X-ray photographic examination, although the amount of radiation is very small, but after all, there will be more or less a certain amount of radiation, it is recommended not to do frequently. It is recommended that women over the age of 40 receive a mammogram once a year. The recommended time is 3~7 days after the end of menstrual period. The examination must be bare upper body, by the pallet clamped to the breast for examination to remove substances that may affect the X-ray penetration, should take the initiative to tell the technician before taking the film, the location of the lump will help to show the lesion, and try to avoid the lesion because of the concealment of the lesion caused by the leakage of the diagnosis.